"Regular treatment with salmeterol for chronic asthma: serious adverse events "

Epidemiological evidence has suggested a link between beta-agonists and increases in asthma mortality. There has been much debate about possible causal links for this association, and whether regular (daily) long-acting beta2-agonists are safe. Thus, this review was done to assess the risk of fatal and non-fatal serious adverse events in trials that randomised patients with chronic asthma to regular salmeterol versus placebo or regular short-acting beta2-agonists. Compared with placebo, mortality increased with regular salmeterol, but this was not statistically significant. Non-fatal serious adverse events increased with salmeterol in comparison with placebo; for every 188 people treated with salmeterol for 28 weeks, one extra non-fatal event occurred in comparison with placebo. No significant differences were found comparing regular salmeterol with regular salbutamol. In patients who were not taking inhaled corticosteroids the two large surveillance studies showed similar sized increases in the risk of asthma-related death. For patients whose asthma is not well-controlled on moderate doses of inhaled corticosteroids, additional salmeterol can give symptomatic benefit but this may be at the expense of an increased risk of serious adverse events and asthma related mortality; risks which are not clearly abolished by inhaled corticosteroids.

Therefore regular salmeterol should be discontinued if no symptomatic benefit is achieved and the manufacturers' advice not to increase the dose of salmeterol during exacerbations should be made clear. Salmeterol should not be used as a substitute for inhaled corticosteroids, and adherence with inhaled steroids should be kept under review if separate inhalers are used.

(Cates CJ, Cates MJ. Regular treatment with salmeterol for chronic asthma: serious adverse events. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD006363. DOI: 10.1002/14651858.CD006363.pub2.)


Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults

Live attenuated varicella vaccines for the prevention of varicella (chickenpox) has been demonstrated both in randomised controlled trials (RCTs) and in population-based immunisation programmes in countries such as the United States. However, many countries do not routinely immunize children against varicella, and exposures continue to occur. Although the disease is often mild, complications such as secondary bacterial infection, pneumonitis and encephalitis occur in about 1% of cases, usually leading to hospitalisation. The use of varicella vaccine in persons who have recently been exposed to the varicella zoster virus has been studied as a form of post-exposure prophylaxis (PEP). The authors concluded that varicella vaccine administered within three days to children following household contact with a varicella case reduces infection rates and severity of cases.

Although in some cases, mild chickenpox may still occur, the vaccine is likely to prevent moderate to severe cases of chickenpox. The number of participants in these three trials was small and is a limitation of this review. No RCTs for adolescents or adults were identified. . It is possible that the efficacy of PEP may be reduced in subjects older than 13 years of age, who require two doses of the varicella vaccine schedule to generate a sufficient primary immune response. Safety of the vaccine in this setting was not adequately addressed.

(Macartney K, McIntyre P. Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD001833. DOI: 10.1002/14651858.CD001833.pub2.)

Intranasal corticosteroids for nasal airway obstruction in children with moderate to severe adenoidal hypertrophy

Adenoidal hypertrophy is generally considered a common condition of childhood. When obstructive sleep apnoea or cardio-respiratory syndrome occurs, adenoidectomy is generally indicated. In less severe cases, non-surgical interventions may be considered. This review was conducted to assess the effectiveness of intranasal corticosteroids for improving nasal airway obstruction in children aged 0-12 years with moderate to severe adenoidal hypertrophy and the authors concluded that “Limited evidence suggests that intranasal corticosteroids may significantly improve nasal obstruction symptoms in children with moderate to severe adenoidal hypertrophy, and this improvement may be associated with a reduction of adenoid size. The long-term effect of intranasal corticosteroids in these patients remains to be defined.” Given the potential clinically relevant benefits and relatively good tolerability of intranasal corticosteroids, these drugs may be indicated as an alternative treatment for children with moderate to severe adenoidal hypertrophy when adenoidectomy is not urgently required or not available.

(Zhang L, Mendoza-Sassi RA, César JA, Chadha NK. Intranasal corticosteroids for nasal airway obstruction in children with moderate to severe adenoidal hypertrophy. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD006286. DOI: 10.1002/14651858.CD006286.pub2.)

Oral zinc for treating diarrhoea in children

Diarrhoea causes around two million child deaths annually. Zinc supplementation could help reduce the duration and severity of diarrhoea, and is recommended by the World Health Organization and UNICEF. This systematic review adds more strength to already robust data in favour of oral zinc in diarrhea. The authors have demonstrated that oral zinc is clearly of benefit in children aged six months or more with acute or persistent diarrhea. More children vomited when given zinc, but it was considered that the benefits outweighed these adverse effects. Zinc seemed to have no impact on children aged less than six months and, there was insufficient data to see any impact on the number of children who died.
(Lazzerini M, Ronfani L. Oral zinc for treating diarrhoea in children. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD005436. DOI: 10.1002/14651858.CD005436.pub2.)

Vigabatrin for refractory partial epilepsy

Approximately 30% of people with epilepsy do not respond to treatment with currently available drugs, and the majority of these people have partial epilepsy. Vigabatrin is an antiepileptic drug licensed for use in the treatment of refractory epilepsy. No major side effects associated with the use of vigabatrin were detected by initial randomised controlled trials of the drug. However, long-term observational studies have subsequently identified that its use is associated with asymptomatic visual field constriction. This review of randomised controlled trials shows that vigabatrin can reduce seizure frequency in people with drug-resistant partial epilepsy. Short-term follow up of patients shows some side effects are associated with its use. Further analysis of longer term observational studies is required to evaluate how likely patients are to develop visual field defects, and whether such side effects are associated with dose and duration of drug use.
(Hemming K, Maguire MJ, Hutton JL, Marson AG. Vigabatrin for refractory partial epilepsy. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD007302. DOI: 10.1002/14651858.CD007302.)

Chest physiotherapy for reducing respiratory morbidity in infants requiring ventilatory support
 
Chest physiotherapy (CPT) has been used in many neonatal nurseries around the world to improve airway clearance and treat lung collapse; however, the evidence to support its use has been conflicting. This review found no clear overall benefit or harm from chest physiotherapy. Some individual chest physiotherapy techniques were more beneficial than others in resolving atelectasis and maintaining oxygenation. These results do not support one technique over another. In view of this and the lack of clear evidence for benefit, it would seem wise to use this intervention cautiously.
(Hough JL, Flenady V, Johnston L, Woodgate PG. Chest physiotherapy for reducing respiratory morbidity in infants requiring ventilatory support. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD006445. DOI: 10.1002/14651858.CD006445.pub2.)

Influenza vaccines for preventing coronary heart disease

This systematic review was done to assess the potential benefit of influenza vaccination for primary and secondary prevention of coronary heart disease, as there is some evidence in favour of the same. However, the authors concluded that despite the significant effect noted in the studies, there are not enough data to evaluate the effect of vaccination on coronary heart disease.
(Keller T, Weeda VB, van Dongen CJ, Levi M. Influenza vaccines for preventing coronary heart disease. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD005050. DOI: 10.1002/14651858.CD005050.pub2.)

-Dr. Puneet Kumar, Kumar Child Clinic, Dwarka, New Delhi
KumarChildClinic@gmail.com